sigtest.php

<?php

$msg = file_get_contents('artifact1.php');

$pubkey_enc = 'RWT/sFZ5HK1Dq173idkKlbBz3gRngoqnchtMp4QdPZpdHJ+8Jpa2ZR8t';
$pubkey = base64_decode($pubkey_enc, TRUE);

$sig_enc = 'RWT/sFZ5HK1Dqz/qStQ9zRdmnZowrMNaMRe/B1gEGRBF+GcEYt95YG/2iN+HNPAddtZVRGaU+QW1NPlhDbtGpvY682aQKvvhBgI=';
$sig = base64_decode($sig_enc, TRUE);
file_put_contents('sig.raw', $sig);

$sig = substr($sig, 10, SODIUM_CRYPTO_SIGN_BYTES);

echo 'Siglen: ';
echo strlen($sig) . "\n";
echo 'Sig should be len: ';
echo SODIUM_CRYPTO_SIGN_BYTES . "\n";

$pubkey = substr($pubkey, 10, SODIUM_CRYPTO_SIGN_PUBLICKEYBYTES);

echo 'Pubkey len: ';
echo strlen($pubkey) . "\n";
echo 'Sig should be len: ';
echo SODIUM_CRYPTO_SIGN_PUBLICKEYBYTES . "\n";

//echo 'Pubkey: ';
//echo $pubkey . "\n";
//echo 'Sig: ';
//echo $sig . "\n";




echo 'Verify: ';
$works = sodium_crypto_sign_verify_detached($sig, $msg, $pubkey);

if ($works) {
  echo "success\n";
} else {
  echo "fail\n";
}